From 1844, the Maltese Cross obliterators were replaced by several series of barred numeral obliterators that gave a coded indication of the place of posting by means of the number allocated to the office. In England and Wales the first day of use was 1st May 1844, with a more gradual introduction in the Scottish and Irish offices in June.
These numbers initially appeared in single numeral cancellations, and later in the “duplex” cancellations which combined a datestamp and an obliterator. Most of these had been superseded by dated stamps by the early 20th century. However, the office numbers were used in instructional and surcharge markings into the 1960s — there are even a few more modern handstamps that use them.
The obliterator types were distinguished by their shape as follows:
England and Wales provincial — oval shaped
Scotland — rectangular shaped
Ireland — diamond shaped
London Districts — oval with number in circle
London Inland Section — oval with number in diamond
